Rare Diseases Research Unit, Department of Pediatrics and Adolescent Medicine, Charles University, Ke Karlovu 2, Prague, 12808, Czech Republic.
Institute of Pathology, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic.
J Inherit Metab Dis. 2018 Mar;41(2):221-229. doi: 10.1007/s10545-017-0108-5. Epub 2017 Nov 22.
Mucopolysaccharidosis type II (MPSII) is a rare X-linked lysosomal storage disorder caused by mutations in the iduronate-2-sulfatase (IDS) gene (IDS, Xq28). MPSII is characterized by skeletal deformities, hearing loss, airway obstruction, hepatosplenomegaly, cardiac valvular disease, and progressive neurological impairment. At the cellular level, IDS deficiency leads to lysosomal storage of glycosaminoglycans (GAGs), dominated by accumulation of dermatan and heparan sulfates. Human induced pluripotent stem cells (iPSC) represent an alternative system that complements the available MPSII murine model. Herein we report on the reprogramming of peripheral white blood cells from male and female MPSII patients into iPSC using a non-integrating protocol based on the Sendai virus vector system. We differentiated the iPSC lines into IDS deficient and GAG accumulating β-Tubulin III neurons, GFAP astrocytes, and CNPase oligodendrocytes. The lysosomal system in these cells displayed structural abnormalities reminiscent of those previously found in patient tissues and murine IDS deficient neuronal stem cells. Furthermore, quantitative determination of GAGs revealed a moderate increase in GAG levels in IDS deficient neurons and glia. We also tested the effects of recombinant IDS and found that the exogenous enzyme was internalized from the culture media and partially decreased the intracellular GAG levels in iPSC-derived neural cells; however, it failed to completely prevent accumulation of GAGs. In summary, we demonstrate that this human iPSC based model expresses the cellular and biochemical features of MPSII, and thus represents a useful experimental tool for further pathogenesis studies as well as therapy development and testing.
黏多糖贮积症 II 型(MPSII)是一种罕见的 X 连锁溶酶体贮积症,由艾杜糖-2-硫酸酯酶(IDS)基因(IDS,Xq28)突变引起。MPSII 的特征是骨骼畸形、听力损失、气道阻塞、肝脾肿大、心脏瓣膜病和进行性神经功能障碍。在细胞水平上,IDS 缺乏导致糖胺聚糖(GAGs)的溶酶体贮积,以真皮素和硫酸乙酰肝素的积累为主。人诱导多能干细胞(iPSC)代表了一种替代系统,补充了现有的 MPSII 鼠模型。本文报道了使用基于仙台病毒载体系统的非整合方案,从男性和女性 MPSII 患者的外周白细胞中重编程为 iPSC。我们将 iPSC 系分化为 IDS 缺陷和 GAG 积累的β-微管蛋白 III 神经元、GFAP 星形胶质细胞和 CNPase 少突胶质细胞。这些细胞中的溶酶体系统显示出与以前在患者组织和鼠 IDS 缺陷神经元干细胞中发现的结构异常相似的结构异常。此外,定量测定 GAGs 显示 IDS 缺陷神经元和神经胶质细胞中的 GAG 水平中度增加。我们还测试了重组 IDS 的效果,发现外源性酶从培养基中内化,并部分降低了 iPSC 来源的神经细胞中的细胞内 GAG 水平;然而,它未能完全防止 GAG 的积累。总之,我们证明了这种基于人 iPSC 的模型表达了 MPSII 的细胞和生化特征,因此代表了进一步发病机制研究以及治疗开发和测试的有用实验工具。